Bellón J M, Buján J, Jurado F, Contreras L A, Hernando A
Department of Morphological Sciences and Surgery, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Madrid, Spain.
J Reconstr Microsurg. 1998 May;14(4):251-8. doi: 10.1055/s-2007-1000177.
The present study represents a long-term investigation of polytetrafluoroethylene (PTFE) vascular microprostheses implanted in the right common iliac artery of rats, with the aim of evaluating the degree of intimal hyperplasia and the changes produced in the vascular prosthesis. A follow-up study was performed between 3 months and 1 year post-implantation, using immunohistochemical techniques, light, and electron microscopy. Three months after implantation, the PTFE segment appeared sandwiched between two cell layers. A general endothelialization was observed on the luminal surface. The underlying myointima appeared as an irregular lining of decreasing thickness, from the distal anastomosis with the receptor artery to the proximal suture. A large number of white blood cells were found adherent to and infiltrating the endothelium. A neoformed adventitia covered the prosthesis on the external surface. At 4 months post-implantation, a destabilization of the luminal surface was observed induced by white blood cells. A progressive reduction in the thickness of the myointimal layer was also apparent, so that 1 year after implantation, the luminal surface of the PTFE prosthesis was fully lined by a thin cell covering. There is good long-term tolerance to implanted PTFE microprostheses. The white blood cells present in the implant region appeared to play an important role in the long-term regression of intimal hyperplasia.
本研究是对植入大鼠右髂总动脉的聚四氟乙烯（PTFE）血管微型假体进行的长期调查，目的是评估内膜增生程度以及血管假体产生的变化。在植入后3个月至1年之间进行了一项随访研究，采用免疫组织化学技术、光学显微镜和电子显微镜。植入后3个月，PTFE段夹在两层细胞之间。在管腔表面观察到普遍的内皮化。下层肌内膜从与受体动脉的远端吻合处到近端缝合处呈现出厚度逐渐减小的不规则内衬。发现大量白细胞附着并浸润内皮。新生外膜覆盖在假体的外表面。植入后4个月，观察到白细胞诱导管腔表面不稳定。肌内膜层厚度也明显逐渐减小，因此植入1年后，PTFE假体的管腔表面完全被一层薄的细胞覆盖物所衬里。植入的PTFE微型假体具有良好的长期耐受性。植入区域中的白细胞似乎在内膜增生的长期消退中起重要作用。
